Arc-lamp.



C. G. HUGHES.

ARG LAMP. APPLIOATIONPILEQ oQT.1s,19o6.

Patented Nov. l?, 1908.

CHARLES C. HUGHES, OF PHILADELPHIA, PENNSYLVANIA.

ARC-LAMP.

Specification of Letters Patent.

Patented Nov. 17', 1908.

Application filed October 13, 1906. Serial No. 338,766.

To all whom it may concern:

Be it known that I, CHARLES C. HUGHES, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia, State of Pennsylvania, have invented certain new and useful Improvements in Arc- Lamps; and I do hereby declare the follow-` ing to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to electric arc lamps of the hot wire type, that is wherein the feed is eected through the medium of a' mechanism including as an element a thermo-ex` pansive wire. I

The object of the invention is to provide an alloy for use in the making of the wire, which alloy will have a high coefficient of expansion, will have a sufficiently high tensile strength to suit the working conditions to which it is subjected, and the eiciency of which will not be impaired when subjected to high temperatures.

A still further and important obj ect of the invention is to produce an alloy vwhich will not only have a high coefficient of expansion but which will be quickly responsive to .changes in temperature.

Numerous attempts have been made to produce a commercially practical lamp of this nature because of its cheapness of manufacture but the difficulty encountered is the proper material for the thermo-expansive element.

In connection with the disclosure of the particular alloy employed, will be illustrated anddescribed a type' of alloy in which the wire has been and is being used.

In the drawings: Figure 1 is a view in ele vation of the lamp, and, Fig. 2 is a similar view, but taken in a vertical plane at right angles to the plane of Fig 1.

The alloy of which the thermo-expansive Wire is formed, consists of copper ftyseven and one-half per cent., nickel forty-two per cent. and lead one-half of one per cent. Of course it will be understood that these speciic' portions of the alloy may be varied as may be found desirable and I do not wish to be limited to the exact proportions specified. Furthermore I may employ the equivalents of the elements mentioned should they be j found to exist.`

Referring now to the drawings in which there is illustrated a lamp of the hot wire type, in which the present alloy is used, the numerals and 6 denote upper and lower plates, respectively, which are held in fixed spaced relation by means of standards 7, there being connected with the upper plate 5 the usual hanger 8 by means of which the lamp may be suspended, and with the lower plate 6, the usual globe supporting device 9.

Extending downwardly from the lower plate 6 is the usual arm 10 which carries at its lower end the usual collar 11 for the reception of the lower end of the lower carbon of the lamp.

Secured to the under side of the upper plate 5 is a plate 12 to which is secured the upper ends of depending guide-rods 13, the

said rods being connected at their lower ends to brackets 14 which extend inwardly from the Standards 7 and overlap at their meeting ends. A collar 15 is arranged for the reception of the upper end of the upper carbon 16 of the lamp, the Said carbon being held in place by means of a set-screw 17 which serves also as a binding post, as will be presently explained.

Extending from diametrically opposite points upon the collar 15 are tongues 18 which are provided with apertures through which extend the rods 13, it being understood that the said rods serve to guide the movementof the upper carbon and that the said carbon extends through an opening formed in the brackets 14 to further guide the same.

Mounted upon the upper face of the upper plate 5 is a binding post 19 which` includes a downwardly extending arm 20 to which arm is connected one arm of an angle bracket 21, the other arm of the angle bracket being apertured for the engagement of a threaded stem therethrough, the said stem being adjustable with respect `to its relative arm by means of a milled nut. Connected with the threaded stem is one end of a conductor wire 22 formed from the alloy above described which extends downwardly as shown in Fig.

1 and around an insulated roller 23 jour- A naled upon a plate 24C which is secured to the adjacent one of the standards 7 adjacent its lower end. The wire 22 extends upwardly and over a similar roller 25 which is' journaled in a bearing bracket 26 secured to the underside of the top plate 5 and over a third roller 27 journaled in a bearing bracket 28 which is also secured to the underside of the said plate. After passing over the roller 27, the wire extends downwardly and around Y an insulated roller 29 and thence upwardly oted arm being made adjustable by providing the arm with a series of openings'33 through which maybe interchangeably engaged the pivot pin which connects the iso members.

V4The plate4 32 is provided with a bracket arm 34 to which is secured the lower end of a plate 35, the upper end f which is bent laterally at right angles and provided with an aperture through which is loosely engaged a threaded stem 36 upon which is engaged an adjusting nut 37 which latter bears against the said portion of the plate 35. A helical spring 38 is connected at one of its ends to the lower end of the stem 36 and is arranged for the engagement of its other end with one of a series of openings 39 formed through the said arm.

Slidably disposed upon the upper carbon 16 of the lamp is a sleeve 40 which is provided adjacent its lower end and upon oppovsite sides. with pairs of spaced fingers between which are received the respective guide rods 13` to prevent turning of the sleeve upon the carbon 16. rIhe sleeve is also provided with a pair of spaced apertured ears between which is pivoted Vone end of an arm 41, the point of pivotal connection of the said arm with the sleeve being adjacent what may be termed the lower longitudinal edge of the arm for a purpose to be hereinafter described. The arm 41 rests against the end of the pivoted arm 31, the said end of the arm 31 being preferably reduced to form a stem 42 and the end of the arm 4l is preferably weighted as at 43 t normally hold it against the stem 42. The

sleeve 40 is provided at a point in alinement with the upper end of the arm 41 with a slot 44 through which the said upper end of thev arm may project to contact with the upper carbon 16, it being understood that the end of the arm contacts frictionally with the said carbon when the arm is raised by rea-v son of the location of the pivot point of the arm adjacent the lower longitudinal edge thereof, and it will also be understood that when the arm is lowered, its upper end will be moved out of engagement with the upper carbon 16v thereby permitting downward movement of the said carbon.

Connected to the binding post 17 is one end of a conductor wire 45 which wire is connected at its opposite end to the binding post 29. The arm 10 has its upper end reduced and screw threaded and engaged through the lower plate 6 and engaged upon the said screw-threaded end of the arm is al nut 47 which, together therewith forms a binding post for the attachment of one end of a conductor wire 48 which is connected at its opposite end to a binding post 49 carried by the upper plate 5. Leading from the binding posts 19 and 48 are the usual wires 50 by means of which the current is conveyed to the lamp,

It will be readily seen from the foregoing that the current of electricity passes through 22 becomes heated and expansion takes place which results in a lengthening of the wire allowing the spring 38 to move theend of the arm 31 to which it is connected upwardly and cause the upper end ofthe arm 41 to engage the upper carbon 16 as heretofore stated and lift the said carbon out of contact with the lower carbon of the lamp.

As the upper carbon burns awayv and agreater length of arc is obtained, the wire 22 becomes cooled and hence contracts, re-

sulting in a downward movement of the end of the pivoted armv31 to which the spring 38 is connected, thereby releasing the end of the arms 41 from engagement with the upper carbon of the lamp and allowing the said carbon to move downwardly. It will of course be understood that .although only one of the clutch actuating arms and the clutch arms themselves have been described, I may duplicate this construction when found necessary to suit certain conditions.

What is claimed is:

1. An arc lamp including a thermo eX- pansive member comprising nickel, copper and lead. f

v2. An arc lamp including a thermo eX- pansive member consisting of an alloy comprising the elements and proportions substantially as follows: fifty-seven and onehalf per cent. copper, forty-two per cent. nickel, and one-half of one per cent. lead.

In testimony whereof, I affix my signature, in presence of two witnesses.

CHARLES C. HUGHES. Witnesses CHAs. W. GLASER, ALICE S. Moss 

